Mounting for drill cutters



Dec. 21 1926. 1,611,284

F. L. SCOTT MOUNTING FOR DRILL CU'QTERS Filed Oct. 20, 1925 Patented Dec. 21, .1926.

UNITED STATES, PATENT OFF-ICE.

FLOYD L. SCOTT, OF HOUSTON, TEXAS, ASSIGNOR T HUGHES TOOL COMPANY, OF HOUSTON, TEXAS, A CORPORATION OF TEXAS.

MOUNTING FOR DRILL CUTTERS.

Application filed October 20, 1925. Serial No. 63,672.

I 'My invention relates to a mountin for the rotary cutters of an earth bOIlIlgdI'l 1. It is intended as an improvement upon the structure shown in the patent to Hughes, No.

930,759, granted August 10, 1909.

In this type of drill, the cutters surround the ends of the converging pins upon which they are mounted and are ordinarily retainedon said pins by contact of said cutters with each other. When the cutters are suspended on the drill head, they will slide down on the pins into contact with each .other. This happens when the drill with the cutters thereon introduced into the 1 5" hole. When the cutters strike the bottom 1' they are forced upwardly on the pins until they are again spaced apart in operative position. The disadvantage of this mounting the cutters lies in the fact'that the cutters, by movin inwardly into contact/with each. other, and away from the side of the hole thus have the effect of narrowing the gauge of the drill during the time the drill is going down into the well bore. It is thereby not 2 adapted to ream the hole to full gauge as it is inserted. I It is an object of my invention to provide a means of holding t e cutters of an earth boring drill apart to the extent of their 80 widest drilling position, so that the cutters may be employed to ream the hole to full augc as the drill is introduced into the well. t is also desired that the cutters be mounted upon bushings of such shape. as to give the cutters the maximum turning movement.

consistent with safety.

Other objects lie in the particular construction and arrangement of parts which will be set out in detail in thespecificationswhich follow. 7

Referring to the drawing herewith, Fig. 1 is a broken side elevation of a drill with the cutters mounted thereon, said cutters and their supporting pins being in central vertical section. Fig. 2 is a lan view of the spreader element employe with the inven tlon. Like numerals of reference are employed to designate like parts in all the views. 7 i The drawin shows the broken lowerend of a drill bit ead 1, made up of two parts fitted together along a central plane 2 The lower end of the ead is formed with an invertedV shaped slot therein, thus providing two outwardly inclined faces'3, 3. The

bearing pins 4, 4 project inwardly from the facesv 3, adjacent the lower edges of the head. Said pins are integral with the head and have a cylindrical threaded portion, 5

and a smooth outer end 6 of smaller diameter. There is an oil duct 7 extending centrally' of each of the pins as isusual with this type of tool. I

The bushing 8 is a sleeve or cap fitting and in side view in the cutter at the right,

in the drawing. I a The cutters 11 are approximately frustoconical and shaped internally to fitthe bush:

.ings 8.

Washers 12, separate the cutters from the faces 3 and thus take up the wear from the head. at the inner sides of the cutters. The apex of each cutter is formed with a cup: shaped recess 13 of suflicient depth to receive a head 14, of the spreader pin 15. Said pin may 'be approximately cylindrical with a frusto-conical shaped head 14, at each end, the said heads being inclined upwardl toward, and in alignment with, the centra axes of the pins upon which the cutters rotate.

The cutters have. teeth 16 cut thereon, as is usual, to cut and disintegrate the bottom and side walls of the hole as the drill is rotated. I v

In operation the cutters will be mounted upon their bushings before the halves of the head are assembled in the position shown in Fig. 1. Then, as the halves of the head are brought together the spreader pin 15, is set in position with the heads 14 thereon fitting within the sockets 13in the ends of the cutters and thus acting to retain them in op-' erative position. -The drill may then be rotated as it is inserted into the hole, and the cutters will, be held outwardly so that they will cut the full gauge of the hole. In

thus reaming the hole the central bottom.

portion of the cutters, adjacent the spreader 15, will do very little cuttingand there will. be no appreciable wear thereon. When the drill reaches the bottom of the hole ready to retaining means, thus avoiding an item of expense and trouble.

Furthermore, the bushings may be made smaller at their largest diameter, and cylin drical so that the cutters may turn more easily, because of the .longer distance between the point of contact of the cutter teeth on the bottom of the hole, and the bushing. There will thus be less wear on the bushings with a resulting longer life.

lVhat-I claim as new and desire to protect by Letters Patent is: i

1. In a roller earth-boring drill including a head having an inverted V shaped recess at the lower end thereof, andconverging cutter pins 011 faces of said recesses, the combination of bushings on said pins, frusto-conical cutters mounted rotatably on said bushings, 'and a spreader pin between the apices of said cutters to retain them rotatably apart 2. In a roller earth boringdrill including a head divided longitudinally, and converging cutter pins on the lower edge thereof, the combination of frusto-conical cutters rotatable on said pins, said cutters having sockets 'in the forward ends thereof and a spreader element fitting in said sockets and acting to maintain said cutters spaced apart.

3. In a roller earth-boring drill including a longitudinally divided head and converging cutter pins formed on the lower end of said head, the combination of bushings on said pins, cutters having central recesses to fit over and enclose the ends of said bushings, and means externally of said cutters to hold them rotatably apart.

4. In a roller earth boring drill having a longitudinally divided head and converging cutter pins formed on the lower .end of said head, the combination of bushings on said pins, said bushings being approximately cylindrical with forwardly tapered ends, cutters having'centr'al recesses to fit over theends of and receive said bushings, and means between the points of said cuttersto hold them apart in the manner described.

- In a roller earth boring-drill including a head divided longitudinally into a plural- .ity of parts, and downwardly converging cutter pins on the lower end thereof, the combination of cutters thereon tapered for- .wardly and inwardly, and'means between said cutters to hold them spaced apart while said cutters are rotated.

6. In a roller earth boring drill including ahead having a transverse inverted V- shaped recess in the forward end thereof, cutter pins on said head converging forwardly, cutters mounted rotatably on said pins, and means between said cutters to re-" tain them spaced rotatably apart.

In testimony whereof,.I hereunto aflix my signature, this the 14th day of October, A.

n, 1925. a 1 v rLoYnn. score. 

